• 제목/요약/키워드: high-tech

검색결과 2,067건 처리시간 0.031초

페로니켈 슬래그를 이용(利用)한 수산화(水酸化)마그네슘 제조방법(製造方法) (Fabrication of Mg(OH)2 from Ferro-Nickel Slag)

  • 박수현;추용식;송훈;이종규;서성관
    • 자원리싸이클링
    • /
    • 제22권1호
    • /
    • pp.42-47
    • /
    • 2013
  • 페로니켈 슬래그는 페로니켈 제조 공정의 부산물이다. 페로니켈 슬래그가 마그네슘 산화물 및 규소 산화물 등 유용 성분을 갖는데도 불구하고 대부분이 폐기되거나 골재로 사용된다. 이 연구는 $H_2SO_4$ 용액을 사용하여 Mg 이온을 추출하고, NaOH 용액을 사용하여 불순물 제거 및 고순도의 $Mg(OH)_2$를 얻으려고 하였다. $H_2SO_4$ 용액에 의해 Mg 이온은 Fe 이온 및 기타 페로니켈 슬래그 구성 성분과 함께 추출되었다. 불순물을 제거하고 고순도의 $Mg(OH)_2$를 얻기 위해서는 침출액의 pH 조절이 중요하다. 불순물은 가수분해에 의한 수산화물 침전으로 제거하였다. 이 과정 후, 여과액에 NaOH를 첨가하여 고순도의 $Mg(OH)_2$을 얻었다.

Steady wind force coefficients of inclined stay cables with water rivulet and their application to aerodynamics

  • Matsumoto, Masaru;Yagi, Tomomi;Sakai, Seiichiro;Ohya, Jun;Okada, Takao
    • Wind and Structures
    • /
    • 제8권2호
    • /
    • pp.107-120
    • /
    • 2005
  • The quasi-steady approaches to simulate the wind induced vibrations of inclined cables, especially on the rain-wind induced vibration, have been tried by many researchers. However, the steady wind force coefficients used in those methods include only the effects of water rivulet, but not the axial flow effects. The problem is the direct application of the conventional techniques to the inclined cable aerodynamics. Therefore, in this study, the method to implement the axial flow effects in the quasi-steady theory is considered and its applicability to the inclined cable aerodynamics is investigated. Then, it becomes clear that the perforated splitter plate in the wake of non-yawed circular cylinder can include the effects of axial flow in the steady wind force coefficients for inclined cables to a certain extent. Using the lateral force coefficients measured in this study, the quasi-steady theory may explain the wind induced instabilities of the inclined cables only in the relatively high reduced wind velocity region. When the Scruton number is less than around 40, the high speed vortex-induced vibration occurs around the onset wind velocity region of the galloping, and then, the quasi-steady approach cannot be applied for estimating the response of wind-induced vibration of inclined cable.

한국·미국 핀테크(FinTech) 산업의 고용창출효과 비교 연구 (A Comparative Study on the Employment Creation Effect of FinTech Industry in Korea and USA)

  • 신용재
    • 디지털융복합연구
    • /
    • 제16권12호
    • /
    • pp.185-195
    • /
    • 2018
  • 본 연구는 한국과 미국의의 핀테크 산업 고용창출효과를 비교분석하여 한국의 핀테크 산업의 발전을 모색하고자 한다. 분석에 사용된 산업연관표는 한국과 미국 모두 동일한 산업분류와 통화 단위로 구성된 WIOD를 이용하였다. 또한 분석을 위해 핀테크 산업을 ICT분야와 금융분야를 하나의 산업으로 구성 하였다. 뿐만 아니라 본 연구는 두 국가의 핀테크 산업 특성을 구분하기 위해 핀테크 산업 외에도 ICT분야와 금융분야의 고용창출효과도 함께 비교하였다. 분석결과, 한국은 핀테크 산업에 100만 달러의 투자 또는 생산이 이루어질 때 취업유발효과는 11.33명, 고용유발효과는 9.47명으로 총20.8명의 고용창출효과를 나타냈고 미국의 경우 취업유발효과는 8.07명, 고용유발효과는 7.72명으로 고용창출효과는 총15.79명으로 나타났으나 절대적인 비교에서는 한국이 더 높게 나타났다. 하지만 국가 산업 전체 평균 고용창출효과를 기준으로 분류한 결과 한국의 핀테크 산업은 고용유발효과가 높은 고용유발우위 산업으로 미국은 취업유발효과와 고용유발효과가 모두 높은 고용창출우위 산업으로 분류되었다.

첨단산업클러스터 형성요인들간의 인과관계분석 (An Empirical Investigation on the Dynamic Relationships among the Critical Factors Influencing on the High-tech Cluster Formation and Its Sustainable Growth)

  • 권성택;김상욱
    • 한국시스템다이내믹스연구
    • /
    • 제7권2호
    • /
    • pp.133-148
    • /
    • 2006
  • This study suggests a Causal Loop Diagram(CLD) of causality mechanism which are integrating matters of localization, networking, embeddedness & institutional thickness and collective learning. These five factors(localization, networking, embeddedness & institutional thickness, collective learning, innovative synergy) have been studied and proofed Also this study suggest a model of industry cluster based on holistic and global system thinking rather than local and linear thinking.

  • PDF

Аnalysis of Venture Capital Trends in Russia

  • Chernova, Vera
    • International Journal of Advanced Culture Technology
    • /
    • 제4권3호
    • /
    • pp.1-5
    • /
    • 2016
  • The article discusses creation and development of venture investment mechanism in Russia. We analyze some tendencies of venture capital funds functioning which should be focused on the financing of development and production of high-tech products, for the period from the creation of the first funds of venture capital investment in 1994 to 2015. The study results may be of interest for business angels and venture capital funds, as well as for public authorities regulating the legal mechanisms to facilitate such investors.

3상 고주파 변압기 최적 설계에 의한 대전력 ZVS 푸쉬풀 컨버터 (A High Power ZVS Push-Pull Converter by Optimized Design of Three-Phase High Frequency Transformer)

  • 박준성;이상원;최세완
    • 전력전자학회:학술대회논문집
    • /
    • 전력전자학회 2010년도 하계학술대회 논문집
    • /
    • pp.135-137
    • /
    • 2010
  • 본 논문에서는 고승압 대전력 3상 DC-DC 컨버터의 핵심부품인 3상 고주파변압기를 상용 EI코아를 이용하여 설계한 방법을 제시한다. 제안한 설계방법은 부피 및 자화인덕턴스 등 불균형 요소를 최소화하고 진동에도 우수한 구조를 갖는다. 5kW급의 시작품으로부터 제안한 컨버터의 타당성 및 성능을 검증한다.

  • PDF

Introduction On the Importance of Engineering Survey in Project Management

  • Meng, Yanlei;Chen, Guiming
    • 국제학술발표논문집
    • /
    • The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
    • /
    • pp.260-262
    • /
    • 2017
  • During the construction of the project, all surveying and mapping work is collectively referred to as engineering survey. Therefore, the measurement work contains a wide range of content, in the engineering survey, design and construction management stage are involved. To the actual work, the project measurement runs through the project building in a number of stages, and provide basic services. This paper mainly through the analysis of engineering measurement at all stages of the role played by the measurement work in the project management work to do the following description.

  • PDF

멜트블론 부직포 제조를 위한 PLA/PCL 블렌드의 미세구조, 열적특성, 및 유변학적 성질 (Microstructure, Thermal Properties and Rheological Behavior of PLA/PCL Blends for Melt-blown Nonwovens)

  • Sun, Hui;Yu, Bin;Han, Jan;Kong, Jinjin;Meng, Lingrui;Zhu, Feichao
    • 폴리머
    • /
    • 제38권4호
    • /
    • pp.477-483
    • /
    • 2014
  • Poly(lactic acid) (PLA) and poly(${\varepsilon}$-caprolactone) (PCL) blends with various components for melt-blown non-wovens were prepared by a twin-screw extruder. Tributyl citrate (TBC) was added in order to improve the miscibility between PLA and PCL. The results showed that small circular particles of PCL were dispersed in PLA matrix uniformly. The addition of PCL had the heterogeneous nucleation effect on the crystallization of PLA and decreased thermal stability of PLA. The flow of pure PLA and blends approached to Newtonian liquid at a low shear rate and expressed more obvious viscoelasticity at a high shear rate.

A New Way to Prepare MoO3/C as Anode of Lithium ion Battery for Enhancing the Electrochemical Performance at Room Temperature

  • Yu, Zhian;Jiang, Hongying;Gu, Dawei;Li, Jishu;Wang, Lei;Shen, Linjiang
    • Journal of Electrochemical Science and Technology
    • /
    • 제7권2호
    • /
    • pp.170-178
    • /
    • 2016
  • Composited molybdenum oxide and amorphous carbon (MoO3/C) as anode material for lithium ion batteries has been successfully synthesized by calcining polyaniline (PANI) doped with ammonium heptamolybdate tetrahydrate (AMo). The as prepared electrode material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscopy (FE-SEM). The electrochemical performance of the anode was investigated by galvanostatic charge/discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The MoO3/C shows higher specific capacity, better cyclic performance and rate performance than pristine MoO3 at room temperature. The electrochemical of MoO3/C properties at various temperatures were also investigated. At elevated temperature, MoO3/C exhibited higher specific capacity but suffered rapidly declines. While at low temperature, the electrochemical performance was mainly limited by the low kinetics of lithium ion diffusion and the high charge transfer resistance.

A Study on description method of product information by utilizing a display specific for store support

  • Hong, Sinyou;Kim, Hyung-O;Ann, Myungsuk;Lee, Seungyoun;Cha, Jaesang
    • International journal of advanced smart convergence
    • /
    • 제4권2호
    • /
    • pp.76-83
    • /
    • 2015
  • Various products are displayed and traded in superstores. Therefore, providing the information of these diverse products plays a crucial part in acknowledging their presence. Currently, superstores mostly utilize printed materials to provide product information and promotion of displayed products. A display equipment is utilized for providing product information and promotion of certain high-end and new products. As such, utilizing an expensive display equipment in order to provide product information fragmentarily for 1 product or successively can be referred to as being inefficient. This paper aims at proposing a method that enables the description of product information efficiently by utilizing a display specific for store support in order to overcome the restriction mentioned above. A test was executed in order to verify the potential of the method of providing product information though the proposed display.